Metal-clad switchgear



3 Sheets-Sheet 1 May 14, 1957 R. E. FRlNK ETAL METAL-CLAD SWITCHGEARFiled Dec. 20. 1954 INVENTORS Russell E. Frnk 8\ P ul Olsson. BY

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5 shets-sheet 5 Filed Deo. 20, 1954 Breaker Open lvIETAL-CLAD SWITCHGEARApplication December 20, 1954, Serial No. 476,104 l2 Claims. (Cl.200-50) Gur invention relates, generally, to metal-clad switchgear and,more particularly, to levering devices and interlocking nechanisms formetal-clad switchgear having removable circuit breaker units.

in metal-clad switchgear a drive-in or levering device is usuallyprovided for mechanically moving the circuit breaker unit between thetest or disconnected position and the operating or connected positionwithin the cell or housing. Also, an interlocking mechanism is providedwhich cooperates with the levering device to prevent movement of thebreaker unit between the test and the operating positions if the breakeris closed and to prevent closing the breaker when it is at any pointbetween the test and the operating positions. T he levering devices andinterlocking mechanisms utilized previously have been somewhatcomplicated in structure. Furthermore, some of them have not functionedproperly all times.

An obiect of our invention is to provide a levering device having asmall number of parts for moving a circuit breaker unit within aswitchgear cell.

Anc-ther object of our invention is to provide for holding the circuitbreaker unit in the test position in the cell.

A further object of our invention is to provide a simple and effectiveinterlocking mechanism for a removable circuit breaker unit.

Still another object of our invention is to coordinate the closingmechanism, the levering device and the interlocking mechanism for acircuit breaker unit in controlling the operation of the circuit breakerand the movement of the breaker unit within the cell.

t EL nited States Patent O Other objects of our invention will beexplained fully l,

hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of our invention, an interlocking linkhas one end connected to the breaker operating mechanism and the otherend so engaging a levering device that operation of the levering deviceto move the breaker unit is prevented if the breaker is closed. Closingof the circuit breaker is prevented when it is at any point between thetest position and the operating position in the cell. A spring-biasedpin holds the levering device and the breaker unit in the test positionand the operating position.

For a better understanding of the nature and objects of the invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawings, in which:

Fig. 1 is a view, partly in side elevation and partly in section, of aportion of a metal-clad switchgear structure embodying the principalfeatures of the invention;

Fig. 2 is an enlarged View, in elevation, of the levering device andinterlocking mechanism for the circuit breaker;

Fig. 3 is an enlarged View, in section, taken along the line III-III inEig. 2; and

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Fig. 4 is an enlarged view, in section, the line lV-IV in Fig. 2.

Referring to the drawing, and particularly to Fig. l, the structureshown therein comprises a portion of a metal-clad switchgear cell orhousing 10 which may be constructed by securing sheet metal members 11to angle frame members 12 in a manner well-known in the art. Vthe cellstructure may rest upon beams 9 disposed upon a suitable foundation. Thecell 10 comprises a circuit breaker compartment 13, and may include acurrent transformer compartment 14, a bus compartment 15, and/or anout-going cable compartment 16. The various compartments are separatedby partition members 17, 1'8 and 19.

A circuit breaker unit 21 is disposed in the breaker compartment 13 andmay be moved horizontally into and out of the cell on wheels 22 whichrun on rails 23 disposed at the bottom of the cell. One form of circuitbreaker and operating mechanism therefore, which may be used, is thatdisclosed in Findley, Oggs and Florschutz Patent No. 2,515,994, issuedJuly 18, 1950. A hinged door 24 is provided at the front of the cell toermit the breaker unit to be withdrawn from the cell.

in accordance with the usual practice, the breaker unit is provided withprimary disconnecting contact members 25 which are disposed to engagestationary contact members 26 which are mounted inside insulatingsleeves 2? disposed inside the cell itl. The disconnecting contactmembers may be of the type described in Patent No. 2,376,818 issued May22, 1945, to M. l. Rubel and assigned to the Westinghouse ElectricCorporation.

A drive-in or levering device is provided for mechanically moving thecircuit breaker unit 21 between the 0perating or connected position andthe test or disconnected position within the cell 10. .in the presentdrawing, the circuit breaker unit is shown in the disconnected position.When the breaker unit is inserted to the connected or operating positionthe disconnecting contact members 25 engage the stationary contactmembers 26, thereby connecting the circuit breaker to power conductors28 which are connected to the stationary Contact members 26.

ln the present structure the levering device comprises a pair of leverarms 31 which are secured to opposite ends of a horizontal shaft 32rotatably mounted in the circuit breaker unit. The shaft 32 is driven bya combined interlocking and levering member 33 which is secured to theshaft 32 and operated by a handle rod or lever 34 in a manner which willbe described more fully hereinafter. A roller 35 is provided at the endof each one of the lever arms 31 and is disposed in a raceway providedbetween angle members 36 and 37 which secured to the side o-f the cell10. Since a lever arm 31 and cooperating angle members are provided atopposite sides of the breaker unit a levering force is provided at bothsides of the breaker unit.

it will be seen that when the shaft 32 is rotated to 'e the arms 31 in adirection indicated by the arrow i l, thc rollers 35 move in theraceways between tte members 36 and 37 which, as previously explained,are secured to the side of the cell structure, thereby drawing thecircuit breaker unit into the cell to the connected Y* sition. When theshaft 32 is rotated in the opposite rection, force is provided throughthe arms 31 to move tie breaker unit from the connected to thedisconnected position shown in the drawings. As indicated by the'broke-n lines, each roller moves through an angle slightly over degreesduring the movement of the breaker unit from the disconnected to theconnected position and moves the breaker a distance approximately twicethe length of the arms 31.

As shown more clearly in Fig. 2 the shaft 32 is mounted taken along inbearing plates 38 which are attached to frame members 39 ofthe breakerunit by bolts 41. The arms 31 may be welded or otherwise secured to theshaft 32. Likewise, the interlocking member 33 and a spacing washer 42are welded to the shaft 32. The interlocking member 33 has threesubstantially equally spaced holes 43 therein for receiving one end ofthe handle rod 34. The shaft 32 may be rotated by inserting the rod 34in one of the holes 43 and moving the rod through an arc as indicated inFig. l. The rod 34 may then be removed and inserted in another hole torotate the shaft 32 still further. As previously stated, three holes areprovided vin the member 33 for the rod 34, thereby permitting threestrokes or operations to be utilized in moving the breaker unit betweenthe connected and the disconnected positions. Y

l An interlocking link.44 has one end connected to an operating member45 of the circuit breaker mechanism by means of a pin 46. The member 45is preferably connected to a part of the closing mechanism for thecircuit breaker whichV moves with the movable contact of the breaker,and it is pivotally mounted on a pin or shaft 47. As shown in Fig. 3 themember 45 moves through an arc between the breaker open and the breakerclosed positions during closing of the contact members of the circuitbreaker. Likewise, the member 45 moves from the breaker closed positionto the breaker open position during opening of the circuit breaker.Thus, the interlocking link 44 is moved longitudinally during operationof the contact members of the circuit breaker. The longitudinal movementof the link 44 is permitted by an oblong opening 48 in the link throughwhich the shaft 32 extends to support the other end of the link 44.

As shown in Fig. 4 one side of the interlocking member 33 has slots orgrooves 51 and 52 disposed therein between raised surfaces 53 and 54. Inthe present instance the slot 51 is slightly wider than the slot 52.

rthe interlocking link 44 has a lugV 55 on one side which is disposed toenter the slot 51 when the circuit breaker unit is in the'disconnectedposition as shown in the drawings. As shown in Fig. 4, one side of thelug 55 engages a surface 56 of the raised portion 53 of the member 33,thereby preventing further rotation of the member 33 in acounterclockwise direction as shown in Fig. 4. Thus further rotation ofthe arms 31 in a clockwise direction as shown in Fig. 3 is prevented. Apositioning pin 57, which is biased upwardly by a spring 58, has entereda notch 59 in the periphery of the member 33 to hold the shaft 32 inthis position. 57 is slidably mounted in a bracket 61 which is attachedto the frame member 39 of the circuit breaker unit by meansof bolts 62.

When the contact members of the circuit breaker are closed the lug 55 onthe interlocking link 44 slides i downwardly into the slot 51, therebymaking it impossible to rotate the shaft 32 and the arms 31 to insertthe breaker unit into the cell with the contact members of the circuitbreaker closed, since the end of raised portion 54 will engage the lug55 and prevent further rota tion. In this position, the roller 35 orlever 31 is opposite the inner side 36 of the raceway which is longerthan the outer side 37, so that the breaker unit is blocked from movingback into connected position in the cell, if Vone should try to do thatwithout using the levering-in mechanism. It will be noted that if theshaft 32 is rotated in a counterclockwise direction as shown in Fig. 3until the pin 57 enters a second notch 63 in the member 33 there will bepractically no forward motion of the breaker unit into the cell, but therollers 35 Will have entered the raccways between the angle members 36and 37, the arms 31 having been moved to a horizontal position. Thus thecircuit breaker unit is held or latched Yin thetestl position by meansof the stop pin 57 which has entered the notch 63. The fact that therollers 35 then engage the outer sideY 37 of the raceway prevents ac-The pin .f

cidental movement of the breaker unit out of the cell.

In this position the contact members of the circuit breaker can still beclosed because of the width of the slot 5l in the interlocking member 33which permits the lug 55 to slide downwardly in the slot 51 withoutengaging the raised portion 54 or" the interlocking member 33. T hisposition of the circuit breaker unit may be considered the test positionand the contact members of the circuit breaker may be closed in thisposition. if it is desired to make the test position and thedisconnected position coineide, the slot 5l may be made the same widthas the slot 52, thereby preventing closing the breaker except in theconnected and the disconnected positions. ln this case the notch 63would be omitted from the member 33.

.if the member 33 is rotated further in a clockwise direction as shownin Fig. 4, orV a counterclockwise direction as shown in Fig. 3, thebreaker unit is drawn into the cell by means of arms 31 and the roller35 as previously explained. The closing of the contact members of thecircuit breaker is prevented while the breaker unit is being movedbetween the test and the connected positions by the lug 55 on theinterlocking link 44 engaging the circular surface 64 of the raisedportion 54 of the interlocking member 33.

When the shaft 32 is rotated to its extreme position in which the lug 55engages a surface 65 of the raised portions 53, the contact members ofthe circuit breaker can be closed since the lug 55 can slide downwardlyinto the slot 52. This is the connected or operating position of thecircuit breaker unit. When the contact members of the circuit breakerare closed, rotation of the shaft 32 to move the breaker unit toward thedisconnected position is prevented by the lug 55 engaging an end surface66 on the raised portion 54 of the interlocking member 33. Itisimpossible to move the circuit breaker to separate the primarydisconnecting contact members when the Contact members of the circuitbreaker are closed. Furthermore, it is impossible to close the contactmembers of the circuit breaker at any point between the test and theconnected positions of the circuit breaker unit.

Position indicators 67 and 68 may be cast on one side of theinterlocking member 33 to line up opposite a name plate on the frame andshow Whether the breaker is in the connected position, the latched-intest position, or the E disconnected position in which the breaker maybe rolled out of the cell. Additional notches 69 and 71 are provided inthe periphery of the member 33 to hold the circuit breaker unit whilethe handle rod 34 is being changed from one hole 43 to another in themember 33. A notch 72 is provided for the pin 57 to hold the circuitbreaker unit in the operating position.

The breaker unit may be provided with a secondary disconnecting deviceof the type disclosed in Haylord Patent 2,276,968, issued March 17,1942. Thus, the necessary control circuits for controlling the operationof the circuit breaker mechanism may be established when the breakerunit is in the test position.

From the foregoing description, it is apparent that We have provided alevering device and an interlocking mechanism which cooperate to providea mechanical means for removing and replacing a circuit breaker unit ina switchgear cell and which prevents movement of the circuit breakerunit between the test and the connected positions when the contactmembers of the circuit breaker are closed. Furthermore, the closing ofthe breaker contact members is prevented when the circuit breaker unitis at any point between the test and the connected positions. Thelevering device and the interlocking mechanism are relatively simple instructure and are suiciently strong to preclude breakage of themechanism under reasonable usage.

Since numerous changes may be made in the abovedescribed construction,and diierent embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that'all mattercontained vin the foregoing description orslrown'in'the accompanyingdrawing shall be interpreted as illustrative iand not "in a limitingsense.

We claim as our invention:

1. in a switchgear structure in combination, a cell, a circuit breakerunit disposed in the cell, operating means for closing contact membersof the breaker, a rotatable levering device for moving the breaker unit'between Aconnected aud test positions inthe cell, an `interlocking linkhaving one end connected to said operating means, the other end of saidlink being actuated by said operating means to engage the ieveringdevice 'to preventmovement of the breaker unit if the contact members ofthe'breakeiare closed, and stop'means on the levering ldevice engaged bysaid interlocking link to limit'the rotation of the levering' device.

2. In a switchgear structure in combination, a cell, a circuit breakerunit disposed in the cell, operating means for closing contact membersof the breaker, a

rotatable levering device for moving the breaker unit fbetween'connectedand test ,positions in the cell, 'aniinterlocking link having one endconnected to said operating means, the other end of said link engagingthe levering 'device to prevent closing the contact members of thebreaker by said operating means when the breaker unit is at any pointbetween the connected position and the test position, and stop means onthe levering device engaged by said interlocking link to limit therotation of the levering device.

3. in a switchgear structure in combination, a cell, a ycircuit breakerunit disposed in the cell, operating means for closing contact membersof the breaker, a rotatable levering device for moving the breaker unitbetween connected. and test positions in the cell, an interlocking linkhaving one end connected to said operating means, said link beingactuated by said operating means to prevent movement of the breaker unitwhen the contact members of the breaker are closed, said link havingmeans thereon engaging said levering device tto prevent closing thecontact members of the breaker when the breaker unit is at any pointbetween the connected position and the test position, and stop means onthe levering device engaged by said interlocking link to limit therotation of the levering device.

4. in a switchgear structure in combination, a cell, a circuit breakerunit disposed in the cell, operating means for closing contact membersof the breaker, a rotatable levering device for moving the breaker unitbetween connected and test positions in the cell, an interlocking linkhaving one end connected to said operating means, said link being movedlongitudinally by said operating means to engage the levering device toprevent operation of the levering device when the Contact members of thebreaker are closed, and said levering device having means thereonengaging said link to prevent closing the contact members of the breakerby said operating means while the levering device is being operated tomove the breaker unit.

5. In a switch gear structure, in combination, a cell, a circuit breakerunit disposed in the cell, a pivoted operating lever for closing contactmembers of the breaker, a rotatable shaft having one or more armssecured thereto engageable with the cell to move the breaker unitbetween predetermined positions within the cell, levering means securedto the shaft for rotating the shaft, an interlocking link having one endattached to said operating lever and the other end movably supported bysaid shaft, said link being movable longitudinally by said operatinglever to engage the levering means to prevent rotation of the shaft tomove the breaker unit when the contact members of the breaker areclosed.

6. In a switchgear structure7 in combination, a cell, a circuit breakerunit disposed in the cell, a pivoted op erating lever for closingcontact members of the breaker, a rotatable shaft having one or morearms secured thereto engageable with the cell to move the breaker unitbetween predetermined positions lWithin the cell, levering .meansysecured to the shaft for rotating the shaft, an interlocking linkhaving one end attached to said operating lever 'and the 'other endmovably supported by said shaft, said link being movable longitudinallyby said operating leve'rto engage the levering means'to preventoperation of the levering means when the contact members of the breakerare closed, and 'said levering means having a raised portion thereon forengaging said link vto prevent 'closing the contact members of theYbreaker while the breaker by said operating lever unit is being movedbetween said predetermined positions.

7. In a switchgear structure, in combination, a cell, a circuitbreakerunit disposed in the cell, a pivoted operating lever for closing contactmembers of the breaker,

Yarotatable shaft having one or more arms secured thereto and engageablewith the cell to move the breaker unit between predeterminedp'ositionswithin'the cell, interlock- -in'g means *secured to the shaft,an interlocking link having one end pivotally attached to said operatinglever,

said link having an oblong opening adjacent the other end, said shaftextending through said opening to support said other end of the link,and said link being movable longitudinally by said operating lever toengage said interlocking means and prevent movement of the breaker unitby rotation of said shaft when the contact members of the breaker areclosed.

8. In a switchgear structure, in combination, a cell, a circuit breakerunit disposed in the cell, a pivoted operating lever for closing contactmembers of the breaker, a rotatable shaft having one or more armssecured thereto and engageable with the cell to move the breaker unitbetween predetermined positions within the cell, interlocking meanssecured to the shaft, an interlocking link having one end pivotallyattached to said operating lever, said link having an oblong openingadjacent the other end, said shaft extending through said opening tosupport said other end of the link, said link being movablelongitudinally by said operating lever to engage said interlocking meansand prevent movement of the breaker unit by rotation of said shaft whenthe contact members of the breaker are closed, and blocking means onsaid interlocking means for engaging said link to prevent closing thecontact members of the breaker by said operating lever while the breakerunit is being moved between said predetermined positions.

9. in a switchgear structure, in combination, a cell, a circuit breakerunit disposed in the cell, a pivoted operating lever for closing contactmembers of the breaker, a

f rotatable shaft having one or more arms secured thereto and engageablewith the cell to move the breaker unit between predetermined positionswithin the cell, interlocking means secured to the shaft, aninterlocking link having one end pivotally attached to said operatinglever, said link having an oblong opening adjacent the other end, saidshaft extending through said opening to support said other end of thelink, said link being movable longitudinally by said operating lever toengage said interlocking means and prevent movement of the breaker unitby rotation of said shaft when the Contact members of the breaker areclosed, said interlocking means having spaced means thereoncorresponding to said predetermined positions of the breaker unit, andspring-biased means engaging said spaced means to hold the breaker unitin said predetermined positions.

lt). In a switchgear structure, in combination, a cell having spacedmembers therein, a circuit breaker unit disposed in the cell, a pivotedoperating lever for closing contact members of the breaker, a rotatableshaft having two arms secured thereto and engageable with said spacedmembers in the cell to move the breaker unit between test and connectedpositions within the cell, an interlocking member secured to the shaftand having spaced slots therein corresponding to the test and theconnected positions of the breaker unit, an interlocking link havingwat@ .one end pivotally attached to said operating lever and an 'oblongopening adjacentrthe other end, said shaft ex- Ytendingthrough saidopening to support said other end sition between said spaced members inthe cell to hold the breaker unit in the test position, a notch on theinterlocking member corresponding to the test position of tlie breakerunit, and a spring-biased pin entering said notch to retain the shaft inthe test position.

11.*In a switchgearlstructure, Yin combination, a cell, a circuitAbreaker unit disposed in the cell, operating means for closing` contactVmembers of the breaker, a

.rotatable levering device for moving the breaker unit vbetweenconnected and test positions in the cell, interlocking meanscooperating. withv saidlevering device to prevent movement of thebreaker unit by rotation of the levering device if the contact membersof the breaker are closed, and spring-biased means for releasablyengaging the levering device to retain the breaker unit in the testposition in the cell.

l2. In a switchgear structure, in combination, a cell, a circuit breakerunit disposed in the cell, operating means for closing contact membersof the breaker, a rotatable levering device for moving the breaker unitbetween predetermined positions within the cell, interlocking meanscooperating with said levering device to prevent movement of the breakerunit by rotation of the levering device if the contact members of thebreaker unit are closed, and spring-biased means for releasably engagingthe levering device to retain the breaker unit in said predeterminedpositions.

References Cited in the le of this patent UNITED STATES PATENTS2,544,314 Hebbel Mar. 6, 1951 ipa m

